This invention relates to display devices.
The present invention seeks to provide a new and inventive form of display device which provides a continuous effect of changing colours.
The present invention proposes a display device which includes a plurality of superimposed light-transmitting walls defining at least one intervening chamber containing two immiscible fluids which are distinguished by colour, in which the said walls are mounted for rotation about an axis which is substantially normal to their plane, and the or each chamber includes means for collecting fluid at one region of the chamber, carrying it to another region of the chamber and releasing the fluid as the walls rotate.
In the present context the term xe2x80x9cdistinguished by colourxe2x80x9d will be understood to embrace the possibility of at least one of the fluids being colourless, white or black.
The fluids preferably have different densities.
The means for collecting and releasing the fluid preferably includes a plurality of cup-shaped recesses disposed at the periphery of the or each chamber.
In a preferred form of the invention the walls define a plurality of chambers containing fluids with different colour combinations.